Air-engine



(No Model.) 2 Sheets--Sheet 1.

E. THUEMMLBR. Air Engine.

No. 232,660. Patented Sept. 28,1880.

wjmessss= mvswm ILPErFJiS, PHOTO-UTHOGRAPHER. WASHINGTON. 0 c4 (NoModel.) 2 Sheets- Sheet 2] E. THUBMMLER.

Air Engine.

No. 232,660. Patented Sept. 28,1880.

WITNESSES: YINVENTDR:

N. PEYERS. PHuTO-LlTn0GRAPMEm WAsmNGToN, I: O4

llNrrno STATES PATENT Erica.

EDWARD THUEMMLER, OF LITTLE ROCK, ARKANSAS.

AIR-ENGINE SPECIFICATION forming part of Letters Patent No. 232,660,dated September 28, 1880.

Application filed March 30, 1880.

To all whom it may concern Be it known that I, EDWARD THUEMMLER, acitizen of the United States, residing at Little Rock, in the county ofPulaski and State of Arkansas, have invented a new and usefulAir-Engine, of which the following is a specification.

My invention relates to air-engines, and the object is to improve theconstruction and effectiveness of those air-engines in which the air isheated by being passed over or between the hot surfaces of a heater orheating-vessel without passing through the fire or the firechamber; andthe invention consists in the construction and arrangement of the parts,as willbe hereinafter more fully described, reference being had to theaccompanying drawings and the letters of reference marked thereon.

In the accompanying drawings, Figure 1 is a vertical longitudinalsection of an air-engine according to my construction. Fig. 2 is avertical cross-section of the working parts on the line 00 w.

Similar letters refer to similarparts in both views.

In the drawings, A is a cylinder, in which a suitably-packed piston, a,is reciprocated, and having an extension, B, in which a piston, O, ofthe kind called the trunk reciprocates through suitable packing y 3Attached to the, piston a is the rod 1), which passes through astuffing-box in the bottom of the trunk O and connects to the cross-head0, and thence, by means of the connecting-rod d, to the crank c. Thecross-head o is guided by the slides ff, which are secured on the insideof the trunk G. The cranks g g are set at about a right angle to thecrank c, and are connected by the connecting-rods h h to the lugs i 03,secured in the bottom of the trunk O.

k k are supports to the crankshaft, on which are fastened the belt andfly-wheels D D.

E is the heater, supplied with a furnace, and so constructed that whileits capacity is small the interior surfaces presented to the passing airshall be extensive.

F is the cooleryconstructed like the heater as to interior surfaces andcapacity, and cooled, preferably, by a -fiow of water through and aroundit. The cylinder Acommunicates with the heater through the pipes Z l andthe valves (No model.)

an m, and with the cooler through the pipes an and the valves 0 0. Thepipes Z and Z are connected by the pipe p, having a valve, (1.

The operation of my engine is as follows: The engine being filled withair, which may be employed in a compressed state, produced by an airpumpworked by the engine itself or by auxiliary power, and the piston (0brought to its uppermost position, the fire in the heater burning, then,on bringing down the piston a, the air in the cylinder A is forcedthrough the heater E by means of the valve m and pipe I, and thence, bythe pipe I and valve m, back into the cylinder A, but on the'upper sideof the piston a. The air, having been greatly heated in its passagethrough the heater, then expands against the trunk G, which precedes thepiston or by reason of its cranks being set at about a right angle inadvance of the crank connected to the piston to, driving up said trunk,while the piston to is comparatively at rest in the lower part of itscylinder A. Then, while the trunk O is at the upper part of its strokeat comparative rest, the piston to moves rapidly upward, driving the airabove it, which cannot. return through the heater on account of thearrangement of the valves m and m, through the cooler F by the valve 0and pipe a, and back into the cylinder A on the under sideof the pistonon through the pipe n and valve 0, thereby abstracting heat andexpansive power, and enabling the trunk O on its downstroke, while thepiston a moves slowly in the upper part of the cylinder A to compressthe air into its original volume, and at the same time to force throughthe cooler F that portion of air which followed the trunk on itsupstroke into the extension-cylinder B. This compression is accomplishedby the expenditure of less power than that developed on the upstroke ofthe trunk G, and the difference is the available power of the engine.The engine has now made one revolution and is on the point of repeating.

The valve q in the pipe 19, when opened more or less, allows a portionof air to pass from beneath the piston a to the space above withoutpassing it through the heater, and thus aproportionally smaller amountof power will be developed. By connecting the valve q to a governor thespeed of the engine may thus be regulated.

By the arrangement I have described I cause the air to circulate throughthe various parts of the engine in one direction only and avoidrepassing it uselessly over either the cooling or heating surfaces whenshifting it from one side of the piston a to the other. The piston amoves in an approximate equilibrium, since a difference of pressure onits two sides will be equalized either through the heater or the cooler,as will be seen by the arrangement of the valves. The spaces in theheater and cooler are respectively sufficient to allow a free passage ofthe air only, but. are collectively of too small a volume to seriouslyaffect the working of the engine by the clearance-space they offer.

taking in a fresh charge at each stroke through the pipe n anddischarging through the pipe n, the valve 0 being then operated bysuitable valve mechanism, which will open said valve and hold it openduring the upstroke of the piston a and the downstroke of the trunk O,to permit the discharge of heated air which has performed its expansion,and at other times will keep said valve closed. I

Except in the case just cited of the valve 0, all the valves except thevalve q may operate automatically, and single valves may be used insteadof double.

I do-not confine myself to the particular construction of engine orvalves shown, as the principle of operation may be carried out byobvious modifications.

I employ the word air to represent, briefly, any vapor, gas, or fluidwhose thermodynamic properties permit of its being employed in themanner and for the purpose set forth in this specification.

I am aware that prior to my invention airengines have been operated bythe alternate heating and cooling of air presented alternately 5 toheating and cooling surfaces. I therefore do not claim such operationbroadly; but

What I do claim as my invention, and desire to secure by LettersPatent,is

1. The method herein described of operating an air-engine by shiftingthe air from one end of a cylinder to the other on opposite sides of apiston reciprocating in said cylinder, thence permitting it to act on aseparate power-piston, and in its course from end to end of saidcylinder causing the air to pass alternately over heating and coolingsurfaces, and always to move in the same direction, substantially asshown, and for the purpose described.

2. The method of operating an air-engine herein described by means of acylinder provided with a packed piston, to, and a piston or trunk, C,said cylinder connected by suitable pipes and valves with aheating-vessel, E, and a cooling-vessel, F, arranged substantially asshown, and for the purpose specified.

3. In an air-engine, the combination of a circulation-cylin der, A, andpiston a, and a power- EDWARD THUEMMLER.

Witnesses:

D. P. OowL, L. BACON.

